This invention pertains to articles consolidated from rubber pieces and particularly to composite solid tires for vehicles, and to a mold and method of making a consolidated filler segment therefor.
Conventional pneumatic tires are filled with air to the pressure required to maintain their configuration and resiliency as they support the weight of a vehicle. However, pneumatic tires are not suitable for use in some industrial applications since they are subject to puncturing and damage from rough use and the necessity of supporting heavy loads.
For such industrial applications various kinds of tires, including solid tires have been proposed. For example: U.S. Pat. Nos. 1,097,824 and 1,369,626. These tires have been made by consolidating a quantity of rubber into the shape of a solid rubber ring, and inserting the rubber ring into a tire casing. Such products have been hard to make, almost impossible to insert inside the casing, and of relatively short service life.
If the rings are made in segments and the segments inserted into the casing to form a jointed core, as also is shown in the prior art, the segments are prone to become dislodged during use of the tire. As a result, insofar as we are aware, there is no composite tire marketed today of the class under consideration.
Tires having a porous solid fill, such as polyurethane foam, are also shown in the prior art. For example: U.S. Pat. No. Re. 29,890. Usually such fills are introduced as a liquid into the tire through the valve stem. They are often too soft for the heavy weight of an industrial vehicle carrying a load. Further, they are costly, tend to wear easily, and are not reuseable if the tire casing becomes damaged or worn out.
There is a need for a solid tire product, however, particularly under heavy duty industrial conditions such as are met by lift truck tires, mobile irrigation sprinkler tires, certain truck tires, etc.
The need for such a tire exists particularly in order to provide a large scale commercial outlet for scrap rubber products, thereby conserving the petroleum resource from which the rubber for present day tires is produced, and also provide a serviceable, low cost, tire product.
It is the general object of the present invention to provide an article consolidated from rubber pieces such as a composite solid tire.
It is a further object of this invention to provide a method of making from scrap rubber pieces consolidated rubber tire filler segments suitable for use in such composite tires.
It is another object of the present invention to provide a mold assembly suitable for forming such tire filler segments.
Another object is to provide a mold assembly having a structure such that the mold may be charged and then sealed while it undergoes heat treatment.
A further object is to provide a sectional mold providing easy access to the molded product.
These and other objects and advantages of the present invention will become apparent in the following specification and claims.